Hundreds of teachers, parents and students across the city picketed outside their schools yesterday in a push to reduce overcrowding.

“There’s not even enough room on the classroom rug for us to sit down,” said Rebecca Anthony, 11, a sixth-grader at PS 126 on the Lower East Side.

The demonstrations were part of a $1 million, multi-front campaign by the United Federation of Teachers and New Yorkers for Smaller Class Sizes to put a class-size referendum on the ballot in November.